6.9 Page 5: D/A Waveform Generator

This is an enhanced features page. It is inaccessible unless enhanced features are enabled.

Page 5, Base + 12 Write Store D/A Code at Address (LSB)

DACA7-0 LSB of address to store D/A code in D/A waveform buffer

Page 5, Base + 13 Write Store D/A Code at Address (MSB)

DACA9-8 MSB of address to store D/A code in D/A waveform buffer

Page 5, Base + 14 Read/Write Waveform Generator Control Register

DEPTH3-0	These bits define the size of the D/A waveform buffer. The depth is based on this equation: Depth = [(DEPTH3-0) + 1] * 64 This allows valid depth values from 64 to 1024 samples. The waveform generator frame pointer will return to 0 whenever it hits either 1024 or the depth value indicated above.
WGCH1-0	These two bits combine to choose how many codes are output on each frame.

WGCH 1	WGCH 0	Description
0	0	1 code per frame
0	1	2 codes per frame
1	X	4 codes per frame

WGSRC1-0These two bits combine to choose which trigger source is used to increment the waveform by one frame

WGSRC 1	WGSRC0	Description
0	0	Manual (using WGINC)
0	1	Counter 0 output
1	0	Counter 1/2 output
1	1	External trigger (J3, pin 45)

Page 5, Base + 15 Write Waveform Generator Command Register

Only one bit can be set to ‘1’ at once. Bits are processed MSB to LSB. The first ‘1’ determines which command is carried out.

WGSTRT	Begin or resume the waveform generator
WGPS	Pause/stop the waveform generator. The current position in memory is saved for the next begin/resume, or can be reset using WGRST.
WGRST	Reset the waveform generator to output from the beginning of the D/A code buffer
WGINC	Force the waveform generator to increment one frame

Details concerning D/A waveform generator can be found in Chapter 14 on page 46.